I have always wanted a generator to go camping, run my Amateur Radio equipment and have it just for emergency power for when the lights go out. I have looked at the commercial units and my club uses a couple of generators every year at Field Day. Field Day is an ARRL radio event to prove that amateur radio operators can still operate without commercial power in an emergency.
Not being able to justify the expense, I saw an article in one of the Back Home or Alternative Power magazines, not sure which one. It had a good article on building your own generator using an alternator from a car. This started to give me some ideals on how it could be used. Most of them if not all of my newer amateur radio gear is 12 volts. I could use converters that take 12 volts DC and convert it to 120 volts AC like what you would use in cars to run TV's and VCR's. I also knew that most of the truckers have microwave ovens and refrigerators in their trucks that run off of converters. I really would not need that kind of capacity but the capability could be there. The only draw back to build one is that you would have to use a car or deep cycle marine batteries for your power source and charge them with the generator.
With all of this in mind, I did not think that it was to much of a set back to use batteries for my power source. The generator also gives me a charger if one of the family cars would not start because the battery was low. Also I would be able to run my amateur radio equipment for hours without running the generator for long periods of time. I would only have to charge when the batteries became low.
I started to collect pieces for this project. As most of you know, there is a ton of old lawn mowers out there that the engines are still good but the wheels and deck of the mower is in bad shape. This is what we can use for our power plant. I had a good friend of mine that gave me a motor that was on his scrap pile. He said it was junk but I had to check it out for myself. I clean the motor up, change the points rebuilt the carburetor and ground the valves. I did not have hardly any money in the motor and it turned out to run really well. I then started to look for an alternator. My brother works with cars as a hobby so he gave me an old one that he had. I now had the basic components to finish the project. I went to an old surplus store and they had a bunch of cast iron pulleys off of military equipment. I found a 5 inch pulley that looked like it would do the job. After I got it home I realized that the shaft on the mower was bigger than the pulley. So I took my lathe and bored the hole out to the size of the shaft.
I made the frame of the generator out of some old bed frames that were being thrown out. Every year in our town we have a week of clean up. That is where you can put items out that normally would not fit in your garbage can. This would be furniture, appliances, etc. I always look for old bed frames it is a great place to get angle iron for my projects. I used pipe for the handle and car valve springs for the legs of the generator. The generator seems not to walk as badly when it is running. From the vibration if you put the generator on the concrete floor it tends to scoot across the floor. The springs help to dampen the vibrations. You might come up with something more unique than mine. Here is a picture of the feet:
I connected the alternator on one side to the frame. This gave me a way to make an idler adjustment screw so you could tighten the V-belt. I made a box so that I could house a volt and amp meter. I used a set of automotive meters. I thought they would be more rugged it I used them instead of meters out of my electronic junk box. It was a good thing that I made the box. When I started to wired the generator, I realized that this alternator was an older one and required a regulator. Newer alternators have the regulator built inside of the housing, so it comes as a complete unit. I mounted the regulator inside of the box with the meters. Here is a picture of the meter box:
From the original article the author did not have any of the material that I had. He bought the cheapest lawn mower from Wal-mart for the motor which I think was about $90. He went to the auto parts store and bought a rebuilt alternator with regulator built-in. He also used angle iron from the hardware store. The type that has the holes in it and cut it to size. The pulley also came from the hardware store. They should have a good variety, a 5 or 6 inch pulley should work well. You will also have to measure and buy a v-belt. So if you do not have a welder you could build this project by building a frame from the hardware store angle iron and bolting every thing together. You also do not need to put the gages on it. I only wanted to do this because I like to visually see what is going on.
I welded every thing together and wired the generator. It turned out very good and I am happy with the project. I have less than $50 in the whole generator including meters. The first time I tried to charge an old junk battery that I had in the garage, it pulled up to 60 amps for a short time and seems to handled it well. Here is a picture of the finished generator: